Deposition of gold containing oxygen thin films was carried out at room temperature onto silicon substrates by reactive magnetron sputtering under Ar/O2 plasma. Nuclear reaction analysis of films shows that different oxygen concentrations (AuOx with x = 0 to 1.2) can be reached depending on the growth conditions. X-ray diffraction and scanning electron microscopy of the deposited samples evidence nanocrystallised films formed of pure Au phase or of Au metal mixed to a low ordered Au2O3 phase. The films display a columnar growth with grains in the 20-30 nm size range. A higher resistivity than that of pure gold is systematically measured by a four probe method. The electrical resistivity of the films was found to be correlated to the mean oxygen amount, and also to the microstructure of the Au phase.